Determination of Young's Modulus for Nanofibrillated Cellulose Multilayer Thin Films Using Buckling Mechanics
2011 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 12, no 4, 961-969 p.Article in journal (Refereed) Published
The Young's modulus of multilayer films containing nanofibrillated cellulose (NFC) and polyethyleneimine (PEI) was determined Using the strain-induced elastic buckling instability for mechanical measurements (SLEBIMM) technique.(1) Multilayer films were built up on polydimethylsiloxane substrates using electrostatic layer-by-layer assembly. At 50% relative humidity, SIEBIMM gave a constant Young's modulus of 1.5 +/- 0.2 GPa for 35-75 run thick films. Conversely, in vacuum, the Young's modulus was 10 times larger, at 17.2 +/- 1.2 GPa. A slight decrease in buckling wavelength with increasing strain was observed by scanning electron microscopy with in situ compression, and above 10% strain, extensive cracking parallel to the compressive direction occurred. We conclude that whereas PEI acts as a "glue" to hold multiple layers of NFC together, it prevents full development of hydrogen bonding and specific fibril-fibril interactions, and at high humidity, its hygroscopic nature decreases the elastic modulus when compared with pure NFC films.
Place, publisher, year, edition, pages
2011. Vol. 12, no 4, 961-969 p.
IdentifiersURN: urn:nbn:se:kth:diva-33242DOI: 10.1021/bm101330wISI: 000289223500013ScopusID: 2-s2.0-79953860258OAI: oai:DiVA.org:kth-33242DiVA: diva2:415291
QC 201105062011-05-062011-05-022011-09-23Bibliographically approved